A magnetic random access memory (MRAM) that is receiving attention as next generation semiconductor technology is replacing a dynamic random access memory (DRAM) having integration limitations. However, while the non-volatility aspects of MRAM devices may be advantageous in terms of schedule, it may be disadvantageous in terms of security. For example, when a computer terminal is powered off and powered on again the user data of a user remains substantially unchanged when transitioning from power on to power off and back to power on. As a result, another user may have an opportunity to steal personal information, such as credit information, of the user. Accordingly, the security of the non-volatile semiconductor memory needs to be improved.